A brother and sister are alleged to have attacked and bitten a neighbour on the leg.
The siblings are also accused of having "pucked" the neighbour's teenage niece in the face after an argument about noise from a house party.
Thomas Walsh (47) and his sister Lucile Walsh (33) went next door to Sinead Lester's house to complain about the loud music and noise, which they described as "outrageous".
They said it was nearly midnight on St Stephen's night and they had young children in bed.
Ms Lester was not in the house at the time, but her niece, Emma Byrne, and five of her friends were in the house eating pizza and listening to music.
They denied the music was too loud, or that they had been drinking, as they were only 17 at the time of the incident.
When Ms Lester returned, she and Ms Walsh got into a verbal argument, which escalated into a fight.
Solicitor Ronnie Lynam claimed the two women were "fighting like cats" and were as bad as each other.
The Walshes denied assaulting Ms Byrne and Ms Lester in the incident in Ashlawn Park, Ballybrack.
Ms Byrne told Dun Laoghaire District Court there was loud banging on the front door around midnight on December 26, 2008.
As she answered it, she said there were four people shouting, "Where the f**k is Sinead? She's dead."
Ms Byrne said the four -- comprising the defendants, another sister and her husband -- tried to push their way into the house.
Ms Byrne said she and her friends managed to close the door, though Ms Walsh hit her as she tried to do so.
The court heard that Ms Byrne was hysterical when she then phoned her aunt, who came home.
Ms Byrne said that when Ms Lester arrived at her front gate, Ms Walsh came from next door and jumped on her aunt, pulling her hair and punching her, and repeatedly banging her head off the ground.
She claimed she then saw Mr Walsh kick her aunt. Ms Byrne said she tried to pull Ms Lester out from under Ms Walsh, and was punched twice on the left cheek.
Ms Lester told the court that she came home and said, "What's the problem?" and then Ms Walsh started attacking her.
She denied in cross examination that she shouted at her neighbours, "Come out, you think you own the road."
A number of Ms Byrne's teenage friends also gave evidence.
They denied claims by the defence that they kicked out at Ms Walsh while she was on the ground. The case was adjourned for legal argument.